1. Technical Field
The present invention relates to an electroluminescent device, a method for manufacturing such an electroluminescent device, and an electronic apparatus.
2. Related Art
Organic electroluminescent (EL) devices have been attracting much attention because the organic EL devices are suitable for display units for use in electronic apparatuses such as personal computers and personal digital assistants (PDAs) and suitable for exposure heads for use in image forming apparatuses such as digital copiers and printers. Japanese Unexamined Patent Application Publication No. 2003-114626 (hereinafter referred to as Patent Document 1) discloses a top emission-type organic EL device. With reference to FIG. 10, the organic EL device includes a substrate 20; thin-film transistors 7; an organic planarization layer 25, containing an acrylic resin, for covering irregularities caused by the thin-film transistors 7; reflective layers 16 arranged on the organic planarization layer 25; light-transmissive first electrode layers 11, electrically connected to the thin-film transistors 7, lying above the reflective layers 16; an organic light-emitting layer 13 lying over the first electrode layers 11; and a second electrode layer 12 lying on the organic light-emitting layer 13, these layers and transistors being arranged above the substrate 20. The organic EL device further includes a protective layer 14 which contains silicon nitride and which lies between the reflective layers 16 and the first electrode layers 11. The protective layer 14 protects the reflective layers 16 when the first electrode layers 11 are formed by patterning a light-transmissive conductive layer. The organic EL device further includes partitions 5 which are parts of a resin layer and which extend along the boundaries between pixels 15.
In the organic EL device, since the acrylic resin for forming the organic planarization layer 25 readily absorbs moisture, moisture contained in the organic planarization layer 25 is transferred to the organic light-emitting layer 13 in some cases, thereby causing the organic light-emitting layer 13 to be degraded. The degradation of the organic light-emitting layer 13 causes defects such as dark spots and therefore is not preferable.
Therefore, as shown in FIG. 10, the organic planarization layer 25 is completely sealed with the protective layer 14 such that the moisture contained in the organic planarization layer 25 is prevented from being transferred to the organic light-emitting layer 13.
Since the protective layer 14 lies between the reflective layers 16 and the first electrode layers 11, the protective layer 14 tends to suffer from stresses caused by end portions of the first electrode layers 11 or the reflective layers 16, whereby cracks 140 are formed in the protective layer 14. This causes a problem that the moisture contained in the organic planarization layer 25 is transferred to the organic light-emitting layer 13 through the cracks 140 to cause the degradation of the organic light-emitting layer 13.